Here’s a bit of a writeup I did for some folks who were being hit with a bout of malware email messages (the actual attachments were being removed by our filters).

The message(s) you received were an attempt to infect your computer with malware, the mail server on receiving the message removed the dangerous attachment but in general if you receive an attachment that you’re not expecting, do not open it – malware writers are creative and may come up with something that the mail server won’t block, at least not while the attack is new. This is the first attempt I remember seeing that pretended to be travel arrangements, but it’s not a surprising development.